Understanding carpet construction, how carpet becomes soiled, and particularly how carpet releases soil is essential to proper carpet care. Developing a thorough understanding of such carpet-care principles forms the basis for successful carpet maintenance planning and often dictates the choice of a specific carpet-cleaning method. The benefits are substantially improved carpet appearance, substantially extended carpet life, and cost-effective carpet maintenance.
On the other hand, a failure to appreciate such carpet-cleaning principles often results in an unreasonable use of discredited carpet-cleaning techniques, particularly wet carpet-cleaning techniques. This, in turn, leads to a number of readily avoidable carpet-maintenance problems. Such problems may be immediately severe and expensive, particularly when occurring on major new carpet installations, or at least will be harmful to the appearance and useful life of the carpet.
Broadly stated, the problems of such wet carpet cleaning techniques involve the retention of too much dirt on and in the carpet, the accumulation of dirt and other residues deep in the carpet, and the damage that water and cleaning solutions can cause. The damage to carpets from wet cleaning methods, in addition to those related to the retention of dirt and solution residues, can include shrinkage, seam splitting, delamination, the formation of mildew and mold, rotting, dye bleeding, dulling, and other discoloration.
Thus, the importance of gaining a clear understanding of carpet construction and conveying such carpet-care principles to the persons responsible for carpet care can readily be appreciated. It is to these ends that this invention is directed and it will be better understood after a brief discussion of certain carpet-care principles.
Carpet includes a pile made up of generally vertically oriented strands of yarns which are attached to a carpet backing. The yarns are made up of many small thin fibers which are twisted together in some fashion. Carpets may have a loop pile or a cut pile, but in either case both the yarns and individual fibers themselves are generally vertically oriented The carpet backing usually includes a primary backing and a secondary backing, the details of which need not be described here. Most carpet soil consists of very small particles, the median particle size being on the order of about 2 microns while a typical carpet fiber to which such particle adheres is on the order of about 40 microns in diameter. The relative size of a typical adhering particle of carpet dirt is so small compared to the size of a single carpet fiber that beside the particle, the fiber surface appears nearly flat.
Most carpet soil is applied by foot traffic. While loose particles typically form about 85% of carpet soil, about 10% of carpet soil is oily. Most soil adheres to the top portion of the pile, primarily to the top one-third of the pile.
Loose carpet soil which may accumulate in the carpet pile is removable by vacuuming, and aggressive vacuuming can even loosen some of the soil adhering to carpet fibers. However, soil which resists vacuuming continues to build up on the carpet fibers and as it builds up, the oily or sticky components tend to increase the rate which soil build-up occurs.
Carpet soil which has adhered to carpet fibers and cannot be removed by vacuuming requires loosening by contact with chemical cleaning agents and brushing. Virtually all carpet cleaning methods bring chemical cleaning agents, usually including water, in contact with the dirt adhering to carpet fibers in order to loosen it. However, the different ways in which this is accomplished have a very great effect on how well carpet is cleaned. While soil loosening is important, removal of the soil from the carpet is the objective.
The many different "wet" carpet cleaning methods, i.e., methods in which a free (flowable) liquid is applied to the carpet in any fashion, loosen the dirt but lose control of it in the process. The dirt is dispersed into the liquid, but only a portion of such dirty liquid is then removed. It is well known that no more than about 80% (and often less) of the free liquid applied to a carpet is removable. Therefore, the dirt and cleaning agents in the remaining liquid remain in the carpet as a residue on carpet fibers, on the carpet backing, and down in the carpet backing.
In contrast, a dry extraction carpet-cleaning method, brings chemical cleaning agents into contact with the dirt adhering to carpet fibers without using free liquid. Many tiny damp particles, made damp with specific carpet cleaning chemicals, are applied to the carpet and brushed through the carpet in a particular manner. The chemical content of the particles loosens the soil adhering to the carpet fibers, and the soil adheres to the particles much in the same way that dirt adheres to a damp sponge after wiping a dirty surface. Indeed, the particle composition, when brushed through the carpet pile, is like millions of tiny sponges scrubbing the carpet fibers.
After the brushing step, the particles are vacuumed from the carpet. The particles are sufficiently large that vacuuming removes the great majority of the particle composition, carrying the dirt and chemical content with it. The particle sizes are also sufficiently large that the particles remain above the carpet backing in position allowing removal by such vacuuming. Thus, such dry extraction carpet-cleaning method provides a high level of control in the dirt-loosening and removing steps--a substantial advantage over wet carpet-cleaning methods. Using this dry extraction method, many of the problems associated with wet cleaning are avoided.
In recent years, an increased awareness has developed within the carpet industry of both the severe disadvantages of wet carpet-cleaning methods and the important advantages of a dry extraction carpet-cleaning method. Such awareness is greatest among those engaged in carpet manufacturing and marketing, where the risks of improper carpet maintenance are often the greatest. Many mills have come to specifically recommend a dry extraction method.
The cleaning industry has not been as quick to appreciate the strong advantages of the dry extraction carpet-cleaning method, and much wet carpet cleaning continues, with all its disadvantages and risks. Some who have an interest in continuing to supply chemicals and machines for old-style wet carpet cleaning have even pooled their resources in a effort to reverse the carpet industry trend toward the dry extraction method.
Those engaged in or concerned with carpet maintenance require technically accurate information regarding carpet care. If they can grasp such information quickly, they will retain it and it will affect their carpet-cleaning decisions.
Various means have been used to demonstrate certain points about carpet cleaning and carpet cleaning methods. Dirt has been dispersed in water and displayed, flat dirt-covered members have been sprayed or wiped to illustrate some of the disadvantages/advantages mentioned above, and the same sort of test has been performed using upright cylinders on a flat base.
There is a clear need for improved methods and means to demonstrate principles relating to carpet care. In particular, there is a need for an improved kit which lends itself to use with a smaller audience of one or a few persons and in a smaller area, such as a desktop, which visually demonstrates the ways in which carpets are constructed and which further demonstrates methods, both discredited and favored, for cleaning carpets.